MDEV-13549 Fix and re-enable MTR test galera.galera_gra_log

Test galera checks that a `GRA_x_x.log` file is created whenever
wsrep applier fails to apply some replication event. The file
contains the corresponding binlog event that failed to apply.
The test creates a new file by concatenating a pre-recorded
file containing the binlog header (see `std-data/binlog-header.log`)
and the `GRA_x_x.log` file. The test then checks that the resulting
file, containing the binlog header and the event that failed to
apply, is correctly read by `mysqlbinlog` program.
The test fails in MariaDB because the GRA_x_x.log file created
by MariaDB already contains the binlog header (see MDEV-7867).
This patch fixes/simplifies test `galera.galera_gra_log` so that
it doesn't concatenate `std-data/binlog-header.log` with the
`GRA_x_x.log` file. File `std-data/binlog-header.log` is deleted
altoghether, because not used by any other test.

mysql-test/suite/galera/disabled.def

@@ -9,7 +9,6 @@
 #  Do not use any TAB characters for whitespace.
 #
 ##############################################################################
-galera_gra_log : MDEV-13549 Galera test failures
 galera_flush :  MDEV-13549 Galera test failures
 galera_account_management : MariaDB 10.0 does not support ALTER USER
 galera_binlog_row_image : MariaDB 10.0 does not support binlog_row_image

mysql-test/suite/galera/r/galera_gra_log.result

@@ -8,22 +8,13 @@ COUNT(*) = 0
 /*!40019 SET @@session.max_insert_delayed_threads=0*/;
 /*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
 DELIMITER /*!*/;
-# at 4
-<ISO TIMESTAMP> server id 2  end_log_pos 120 	Start: binlog v 4, server v 5.6.24-debug-log created 150804 11:37:14 at startup
-# Warning: this binlog is either in use or was not closed properly.
 ROLLBACK/*!*/;
-BINLOG '
-unnAVQ8CAAAAdAAAAHgAAAABAAQANS42LjI0LWRlYnVnLWxvZwAAAAAAAAAAAAAAAAAAAAAAAAAA
-AAAAAAAAAAAAAAAAAAC6ecBVEzgNAAgAEgAEBAQEEgAAXAAEGggAAAAICAgCAAAACgoKGRkAAKNu
-Jfk=
-'/*!*/;
-# at 120
-<ISO TIMESTAMP> server id 1  end_log_pos 91 	Query	thread_id=<QUERY_THREAD_ID>	exec_time=0	error_code=0
+ROLLBACK/*!*/;
 use `test`/*!*/;
 SET TIMESTAMP=<TIMESTAMP>/*!*/;
 SET @@session.pseudo_thread_id=<PSEUDO_THREAD_ID>/*!*/;
 SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=0, @@session.unique_checks=1, @@session.autocommit=1/*!*/;
-SET @@session.sql_mode=1073741824/*!*/;
+SET @@session.sql_mode=1342177280/*!*/;
 SET @@session.auto_increment_increment=1, @@session.auto_increment_offset=1/*!*/;
 /*!\C latin1 *//*!*/;
 SET @@session.character_set_client=8,@@session.collation_connection=8,@@session.collation_server=8/*!*/;

mysql-test/suite/galera/t/galera_gra_log.test

@@ -19,17 +19,10 @@ CREATE TABLE t1 (f1 INTEGER);
 --connection node_2
 SELECT COUNT(*) = 0 FROM t1;
 
-# Compose a valid binlog from a header file and the GRA file
+# Make sure the GRA file produced is readable and contains the failure
 
---let $gra_binlog_file = $MYSQLTEST_VARDIR/tmp/gra.log
---exec rm -rf $gra_binlog_file 
-
---exec cp std_data/binlog-header.log $gra_binlog_file
---exec cat $MYSQLTEST_VARDIR/mysqld.2/data/GRA_*.log >> $gra_binlog_file
-
-# Make sure the binlog thus produced is readable and contains the failure
---replace_regex /SET TIMESTAMP=[0-9]+/SET TIMESTAMP=<TIMESTAMP>/ /#[0-9]+ +[0-9]+:[0-9]+:[0-9]+/<ISO TIMESTAMP>/ /pseudo_thread_id=[0-9]+/pseudo_thread_id=<PSEUDO_THREAD_ID>/ /thread_id=[0-9]+/thread_id=<QUERY_THREAD_ID>/
---exec $MYSQL_BINLOG $gra_binlog_file
+--replace_regex /SET TIMESTAMP=[0-9]+/SET TIMESTAMP=<TIMESTAMP>/ /pseudo_thread_id=[0-9]+/pseudo_thread_id=<PSEUDO_THREAD_ID>/
+--exec $MYSQL_BINLOG --short-form $MYSQLTEST_VARDIR/mysqld.2/data/GRA_*.log
 
 SET SESSION wsrep_on=ON;